One problem related to transfer case has been reported for the 2011 Toyota Highlander. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2011 Toyota Highlander based on all problems reported for the 2011 Highlander.
Vehicle makes a very noticeable, irritating whine or whistle noise when accelerating at 40mph. Stops when gas pedal is released. Very constant and annoying. Did not happen when car was first purchased. Have been told by Toyota that it was the transfer case, which they replaced. Did not fix the problem. Now they tell me it is normal. Test drove another vehicle from their lot of the same exact year, make, model. No noise at all. This is not normal. Toyota knows about the problem, but they are denying it. Other Toyota vehicles (I. E. Rav4, tundra) had/have the same problem. Forums tell me it is the transmission. Waiting on appointment for a field tech from Toyota to examine it.